1. Field of the Invention
The present invention relates generally to an automatic transmission arrangement for automotive vehicles. Particularly, the present invention relates to an automotive automatic transmission in which efficient use of space is utilized for reducing a necessary size of the transmission.
2. Description of the Prior Art
Conventionally, in an automotive automatic transmission, a hydraulically operated mechanism is arranged in an end portion thereof. For example, a multi-plate type brake utilizing a plurality of clutch plates, a piston and a return spring may be arranged in an end portion of the transmission casing or at a side cover portion of the transmission.
For example, in Toyota A240 Automatic Transmission Shuurisho (Repair Manual) pg. 3-4 (Published December, 1986 by Toyota Motors Co. Ltd.) such type of automatic transmission is disclosed in which a piston and a return spring are accommodated in a cylinder chamber provided at and end portion of the transmission casing. The cylinder chamber is connected with a multiplate clutch provided in a central portion of the transmission casing.
Further, in Toyota Model A140 and Model A141, Automatic Transmission Repair Manual, pgs. 3-7 and 3-8 respectively (Published May 24, 1985 by Toyota Motors Co. Ltd.), as well as Mitsubishi Automatic Transmission KM170, KM171, KM172 and KM175 Complete Equipment Manual (Seibi Kaisetsusho), pg. 5 (Published October 1983 by Mistusbishi Motors Co. Ltd.) automatic transmissions are disclosed in which a cylinder chamber accommodates a return spring. A vertical wall portion is formed at the side cover of the transmission and clutch plates are arranged between the wall and the cylinder chamber.
In the above-mentioned prior art automatic transmissions it is required that a vertical wall portion be provided in the transmission casing either at the side cover or within the casing itself. Transmission structures requiring such a wall portion cause an axial measurement thereof to be increased.
Also, according to the above-mentioned prior art automatic transmissions, since the hydraulically operated clutch, or brake must be installed followed by installation of the side cover over the open end of the transmission casing, to manufacturing steps are required at this stage, increasing the cost and complexity of manufacturing an automatic transmission.
In modern automotive technology, a compact transmission with reduced axial length has been required.